1. Field of the Invention
The present invention relates to a device for assembling a bracket with a shaft, and more particularly to a device for assembling a steering column bracket with a steering gear of an automobile vehicle, which device constitutes the connection of the steering column with the steering box.
2. Description of the Prior Art
There exist many devices for assembling a steering column with the gear of the steering box of an automobile vehicle. When the steering column has a bracket at the bottom, the bracket is very often equipped with a nut-and-bolt transverse to the axis of the bracket.
The nut-and-bolt clamps the two branches of the bracket against the shaft of the steering gear, pressing on each of the outside faces of the branches of said bracket. Assembly devices of the above type require an environment in the vehicle that enables easy access when mounting and clamping, and it is also necessary to provide special tools for correctly offering up the nut during mounting and insertion of the bolt, and which prevents the nut from rotating during tightening. Finally, assembly devices of the above type do not guarantee continuing clamping during use of the vehicle.
The object of the present invention is to propose a device for assembling a steering column bracket with a steering gear which avoids the drawbacks described above and which allows particularly simple blind mounting in a confined space and without special tools and guarantees a permanent assembly.
One embodiment of the invention relates to a device for assembling a bracket to the end of a shaft which is engaged in the bracket. The device for assembling includes a system for clamping and immobilizing the shaft in the bracket, which system is constituted by a clamping bolt cooperating with a clamping nut along a clamping axis, in which device. In this configuration:
the clamping nut is disposed in one branch of two branches of the bracket;
the clamping bolt passes through the other branch of the bracket;
the clamping nut is held in place against rotation and translation along the clamping axis by an antirotation elastic member for pressing the clamping nut against the outside face of the branch of the bracket;
the outside periphery of the clamping nut is provided with a radial protrusion;
an axial prepositioning abutment is adapted to be fastened to the bracket;
when the radial protrusion of the clamping nut is pressed against the axial prepositioning abutment, the clamping nut is partly withdrawn along its axis to allow the bracket to be engaged over the end of the shaft; and
the antirotation elastic member is adapted so that, at the end of tightening the clamping bolt in the clamping nut, the clamping bolt neutralizes the antirotation function of the antirotation elastic member in order to allow the clamping nut to escape from the axial prepositioning abutment and immobilize the bracket on the shaft.
According to an embodiment of the invention, the axial prepositioning abutment is integrated with the bearing antirotation elastic member. According to another embodiment of the invention, the axial prepositioning abutment is integrated with the bracket.
In a general structure of embodiment of the invention, the clamping nut includes:
a cylindrical body adapted to be mounted in a hole formed in a corresponding branch of the bracket;
a flange adapted to be pressed against the outside face of the branch of the bracket;
the radial protrusion, which is disposed at the periphery of the bearing flange, and which is pressed against the axial prepositioning abutment when engaging the bracket over the end of the shaft; and
an inside cylindrical end which extends the cylindrical body into the housing of the bracket, the inside cylindrical end being eccentric to the cylindrical body so that the eccentric inside cylindrical end is on the opposite side of the shaft to the clamping axis when the clamping and immobilizing system is in an unlocked position;
so that at the end of tightening the clamping bolt in the clamping nut, and after neutralization of the antirotation function of the antirotation elastic member, the clamping nut can turn about the clamping axis and the eccentric inside cylindrical end can be pressed against a flap provided on the shaft.
According to a general structure of embodiment of the invention, the antirotation elastic member includes:
a connecting portion for connecting it to the bracket;
a bearing antirotation portion; and
a flexible connecting portion connecting the bearing antirotation portion to the connecting portion to constitute a single member.
In a detailed structure of the antirotation elastic member:
the connecting portion of the antirotation elastic member has a U-shaped section with two branches and a connecting base so as to surround the external part of the bracket, each of the two branches having a curved end which is engaged in a housing formed on the corresponding branch of the bracket, and the connecting base including two bearing elastic tongues which are opposite each other in the axial direction;
the bearing antirotation portion of the antirotation elastic member includes two bearing antirotation tongues which are connected together by an end base; and
the flexible connecting portion of the antirotation elastic member includes two flexible branches which are connected to the connecting base of the connecting portion and to the corresponding bearing antirotation tongue.
Advantageously, the axial prepositioning abutment is integrated with one of the branches of the connecting portion of the antirotation elastic member.
In a detailed structure of the antirotation elastic member:
the clamping nut includes:
a bearing cylindrical base,
an antirotation portion which is an axial extension of the bearing cylindrical base and includes two flaps, the first flap and the second flap being substantially parallel to each other; and
an external cylindrical end which axially extends the antirotation portion, the transverse overall size of the outside cylindrical end not exceeding the distance between the first flap and the second flap.
So that at rest, i.e. before clamping, the two bearing antirotation tongues of the bearing antirotation portion are pressed against the outside face of the bearing cylindrical base of the flange and at the end of clamping the end of the clamping bolt pushes back the end base which entrains the two bearing antirotation tongues in the axial direction to disengage them from the antirotation portion.
Advantageously, the eccentric inside cylindrical end of the clamping nut is provided with a face inclined to the clamping axis to enable insertion of the shaft in a direction parallel to the uprights of the bracket.
Furthermore, the inside cylindrical end of the nut is eccentric to the cylindrical body and the inside cylindrical end and the cylindrical body have a common generatrix on the opposite side of the shaft relative to the clamping axis when the clamping and immobilizing system is in an unlocked position.
A particularly interesting application of the invention refers to a steering column of an automobile vehicle and wherein the bracket is mounted on the steering column and the shaft is the shaft of the gear of the steering box.
The device in accordance with the invention for assembling a steering column bracket with a steering gear of an automobile vehicle therefore has the advantage of allowing mounting with the clamping nut held in position; this avoids all risk of loss and allows assembly blind in a restricted space. Also, the locked position with the nut immobilized against the shaft guarantees that the bracket is maintained in position on the shaft with the required tightness.